Control means for refrigerating apparatus



Jan. 10, 1939. F. H. H IBBERD I CONTROL MEANS FOR REFRIGERATINGAPPARATUs Filed NOV. 16, 1957 Hi5 ATTORNEY- Patented Jan. 10, 1939UNITED STATES 3 Claims.

The invention relates to refrigerating apparatus wherein the temperatureconditions, under which the apparatus is operating, control theoperation of the apparatus. It relates more particularly to the type ofrefrigerating apparatus wherein evacuating means remove vapor from anevaporator and discharges it into a condensing means which is cooled byfluid medium. Accordingly, an object of the inventionis to control theoperation of the evacuating means by the temperature of the fluid mediumin the condensing means.

Another object is toprevent waste of the power refrigerant to the pointwhere the refrigeration is required. An inlet pipe 1 returns the warmedrefrigerant to the chambers of the evaporator.

Separate evacuators 9 and I I are provided for each chamber in theevaporator.

The evacuators are of standard construction and are operated by steamsupplied through the pipes I3 and I5. These pipes connect with a commonheader Handare controlled by valves I9 and 2|. The evacuators remove thevapor from the evaporator and discharge it into a condenser 23 tvhichmay be of any standard construction, using a liquid cooling medium suchas water.

The condenser 23 is supplied with cooled water through a cooling watercircuit consisting of a conduit 25 leading to an open cooling tower 21.Water is removed from the bottom of the cooling tower through the pipe29 by the pump 3| and is returned to the condenser by the header 33.

The structure thus fsrdesorlbed is a conventional type of refrigeratingapparatus which operates satisfactorily for the most part. Occasionally,however, when the refrigerating load is heavy, the evacuators willdischarge so much hot vapor into the condenser that the coolingwaterwill be unable to remove all the heat. In other words, the temperatureof the cooling PATENT OFFICE CONTROL MEANS FOR REFRIGERATING APPARATUSFrederick Hyde Hibberd, Harrison, N. Y., assignor to Ingersoll-RandCompany, Jersey City, N. J a corporationof New Jersey ApplicationNovember 16, losasenal No. 174,774

water becomes so high before it leaves the condenser will not becondensed and a rise in temperature with a corresponding increase inpressure will occur. Such conditions in the condenser will cause theload to surge in the evacuators or fbreak back through the evacuators,suspending refrigeration with the accompanying losses ofpower andrefrigerating effect. In order to preventsu'ch conditions from occurringit is proposed tocontroi the operation of the evacuator II in accordancewiththe temperatures 0 the condensericooling water. i

. In the form 'illustrated a thermostat 35 is provided in the pipe 29leading from the bottom of the air cooler to the pump. This thermostatis connected to a valve 31 and controls the action of this valve.

In the operation of the apparatus, the evacuators 9 and I I remove thevapor from the chambers 3 in order that the refrigerant in the chambersmay be chilled. The vapor is discharged into the condenser 23 and thechilled refrigerant is removed from the evaporator by pipes 5 and thenreturned to the chambers by pipes 1.

Under normal operating conditions, the refrigerant is returned to theevaporator I at a temperature high enough to prevent the evacuators 9and II from lowering'the temperature in the evaporator chambers to thefreezing temperatures and low enough that the heat load on the condenser23 is such that the condensing water is sufiiciently cooled by the watertower 21 that it returns to the condenser 23 at a temperature low enoughto prevent surging of the load on the evacuators 9 and II since all thevapors discharged into the condenser 23 are condensed. Under suchconditions the thermostat 35 will maintain the valve 31 open.

[ However, if the volume of vapor discharged ina to the condenserincreases, the temperature of the cooling water leaving the condenserincreases. As the temperature increases, the temperature of the coolingwater returned to the condenser is correspondingly higher and not all ofthe vapor introduced into the condenser will be condensed so that vaporwill accumulate in the condenser which, with the increase in temperaturecausing an increase in pressure, will greatly increase the pressureagainst which the evacuators discharge.

With present arrangement, however, when this occurs the increase oftemperature of the cooling water will actuate the thermostat causing itto close the valve 31 and thereby shut off the power supply to theevacuator ll. Thus the evacuator ii may be shut down or intermittentlyoperated in order to reduce the heat load on the condenser and preventcondenser pressure from exceeding the point at which surging of the loadwould occur. Without some means of shutting ofi the load on thecondenser the conditions would get progressively worse until theapparatus would cease to function.

In this manner some of the evacuators may be kept in operation tomaintain refrigeration and at the same time steam power will be saved.Thus, absolute break of the refrigeration may be prevented.

It will be understood that the foregoing disclosure is illustrative onlyand that the invention is not limited to the control of one evacuator orto systems embodying two evacuators.

I claim:

1. In a refrigerating apparatus, a multichamber evaporator, a steamevacuator for each chamber of the evaporator, a steam supply conduit forthe evacuators, branch conduits connecting each evacuator to the steamsupply conduit, a water cooled condenser to receive the discharge of theevacuators, an outlet conduit to remove cooling water from thecondenser, a cooling tower to receive and cool the condenser coolingwater discharged by said outlet conduit, a cooling tower water outletconduit to remove cooling water from the cooling tower and discharge itto the condenser, a thermostatically operated valve in one of saidbranch conduits, and a thermostat in said cooling tower outlet conduitto operate the valve to control the flow of steam to the respectiveevacuator in accordance with the temperature of the condenser coolingwater leaving the cooling tower.

2. In a refrigerating apparatus, a multi-chamber evaporator, a steamevacuator for each chamber of the evaporator, a steam supply conduit forthe evacuators, branch conduits connecting each evacuator to the steamsupply conduit, a water cooled condenser to receive the discharge of theevacuators, an outlet conduit to remove cooling water from thecondenser, a cooling tower to receive and cool the condenser coolingwater discharged by said outlet conduit, a cooling tower water outletconduit from said cooling tower to said condenser, a pump interposed insaid cooling tower outlet conduit to discharge cooling water from thecooling tower to said condenser, a thermostatically operated valve inone of said branch pipes, and a thermostat in said cooling tower outletconduit to actuate said thermostatically operated valve to control theflow of steam to the respective evacuator.

3. In a refrigerating apparatus, a multi-chamber evaporator, a steamevacuator for each chamber of the evaporator, a steam supply conduit forthe evacuators, branch conduits connecting each evacuator to the steamsupply conduit, a water cooled condenser to receive the discharge of theevacuators, an outlet conduit to remove cooling water from thecondenser, a cooling tower to receive and cool the condenser coolingwater discharged by said outlet conduit, a cooling tower water outletconduit from said cooling tower to said condenser, a pump interposed insaid cooling tower outlet conduit to remove cooling water from the towerto the condenser, a manually operated valve in each said branch conduitto control the flow of steam therethrough, a thermostatically operatedvalve to control the flow of steam in one branch pipe, and a thermostatin said cooling

